Apparatus for carbonizing coal



July 20 1926.

C. HAYES APPARATUS FOR CARBONIZING COAL Filed May 22, 1926 Patented July 20, 1926.

UNITED S A ES-{PATENT OFFICE.

CHARLES HAYES, OF PARIS, FRANCE.

AI PPARATUS FOR CABBONIZING COAL.

Application filed Kay 22, 1926, Serial No. 110,947, and in Canada May 16,1925.

My invention relates to apparatus for carbonizing coal and has for its object to provide a simple, eflicient and inexpensive apparatus b containing an excess of volatiles may be so far freed from volatiles as to leave a cokelike product high in fixed carbon with only such proportion ofvolatiles as may be desired for the purpose of enablin it to be readily ignited.

The value of coal for use as fuel depends upon the proportionate content of fixed carbon. If not too high in volatiles it may be used as steam coal or may be coked. But there are large deposits of coal which are so high in volatiles as to be non-coking and of little value as fuel. This is particularly true of the coal classed as lignite which is not only high in volatiles but also carries a large percentage of water.

By my invention this non-coking coal and ligmte may be quickly and at little expense freed from excess of volatiles and water so as to leave a product composed mainly of fixed carbon free from water and containing only such slight percentage of volatiles as ma be desired to make the product easy to ignite The product obtained by'the use of my a paratus is coke-like and is well adapted For use as. domestic fuel as well as for use for any other fuel purpose, and is particularly uniform in quality whatever the original material fromwhich it is made. The volatiles driven off are largely composed of condensable vapors and the oils condensed from these vapors are of substantial value and the volatiles driven off as fixed gas are of value for heating the digesters or for sale as gas for heating or illuminating.

With the objects above indicated in view my invention consists in the apparatus hereinafter described and claimed;

Referring to the drawings Figure 1 is a vertical sectional view, partly diagrammatical, of a plant embody- 111% my invention.

igure 2 is a detail plan view of the piston-of one of the digesters.

Fi 7 re 3 is a detail plan and vertical sectiona view showing the construction of the di ester bottom.

n the drawings 1 indicates a chamber preferably of brick work having arranged therein two or more vertical digesters 2 pref: erably tubes or cylinders of iron or steel.

which coal and coal-like material to the digester, this construction being adapted to be readily locked and released and when locked in closed position capable of supportingheavy pressure. p

In each digester is arranged a piston 10 carried by a rod 11 extending through guide plate 12 into a cylinder 13 arranged above the top of chamber 1-and carrying a piston 14. Water or oil supplied to cylinder 13 by pump 16 serves to force the piston 10 downward or to withdraw it as desired.

Below the lower ends of the digesters 2 is a bin 20 the bottom 21 of which is arranged at a distance from the lower end of the digester about equal to half the vertical height of the digester so. that when the bottom of the digester is opened and the piston 10 is operated to expelthe lower portion of the charge, this expelled portion being a solid mass of coke-like material with its lower end resting on the bottom 21 of the bin forms a supporting column by which the less solid upper portion of the charge will be supported and prevented from-dropping out of the digester. When the bottom is again closed this less solid portion of the charge will be in the lower portion of the digester in position to be subjected to the re atively higher heat and to be formed into a solid coke-like mass. A door 22 at one side of the bin 20 permits the finished product to be removed.

About the wall of the bin is arranged a chamber .or tank 23 to be supplied with water to be converted into steam y the heat of the material discharged from the digester. The mass of material may, if desired be cooled by water from a hose or by other means.

About the digesters 2 between them and the walls of chamber 1 are preferably arran ed baflle plates 25 and beneath these ba 0 plates are burners 26 preferably for burning fuel oil through the digester may, of course, be heated by other means. The air necessary for combustion may be supplied to these burners in any usual manner as by an air pipe 51 surrounding the oil pipe 52. Between the baflie plates is arranged a coil 27 which is supplied with steam from any convenient source the coil 27 serving to superheat the steam so supplied. The upper end of the coil 27 is connected with pipes 28 preferably three for each digester, leading through the guide plate 12 downward nearly to the lower end of the digester, these pipes being perforated at intervals from their lower ends to a point about opposite the midlength of the digester. The pistons 10 are provided with suitable openings for these superheated steam pipes. The three superheated steam pipes for digester are preferably equally spaced apart and at points about midway between the center of the digester and its inner periphery. I

Near the upper end of each digester is an inlet opening 30 to which leads a pipe 31 from a supply pipe 32 which leads from conveyor 33. here shown as a screw conveyor of ordinary construction operated by a pulley 34. This conveyor is adapted to receive coal or other material from a bin 35 and discharged it into pipes 31 and so into the digesters.

The coal or other material is supplied to bin 35 from a preliminary heater 36 arranged to be heated by burner 37 and having at its outer end a hopper 33 to which the coal is supplied preferably broken so that its particles will not be too large to pass through a quarter inch screen. The air necessary for combustion may be supplied to these burners in any usual manner as by an air inlet pipe 53 surrounding the oil supply pipe 54. This preliminary heater is arranged to be rotated, by a motor 39 so as to effect agitation sulficient to prevent the particles of coal from sticking together and to ensure even heating.

From the upper part of chamber 1 a pipe 40 leads to chamber 41 in which by means of a rotary screw 42 driven by motor 43 any particles of dust or other solid matter carried over from the digester will be thrown outward against the walls of the chamber to collect at its bottom.

The gas and vapors pass from chamber 41 by pipe 45 for such separation of the vapors and recovery of condensates therefrom and such use of the fixed gas as may be desired.

By compressing the coal while it is in relatively soft condition the formation of gas pockets is prevented and the material is made dense and solid the resulting fuel being more dense and solid than ordinary coke and having a specific gravity about the same as that of the raw material used. By reason of its density and relatively high specific gravity the finished product is adapted to be transported at lower freight rates than ordinary coke.

In carrying out the process the coal or lignite previously crushed is introduced into the preheater 36 where it is subjected to a heat of about 400 degrees F., the preheater being agitated to ensure evenness of heating. From the preheater 36 the heated coal is discharged into bin 35 from which it is conveyed by conveyor 23 to the upper end of the digester which is heated by burners 26 arranged at its base'so that its lower portion is more highly heated than its upper portion thus forming a lower high heat zone and an upper less heated zone. \Vhen the digester is filled with the preheated coal the plunger 10 is operated to compress the charge of coal the effect of this first compression being to force the particles of coal into a compact mass free from any large air or gas pockets. The heat being greater towards the lower end of the digester the coal in that portion of the digester becomes quickly softened and the coal in the upper portion becomes more or less softened. The plunger is then again operated compressing the softened coal into a compact mass and leaving a considerable space above it. Additional coal is then fed into the upper end of the digester until it is full, and the plunger is operated to compress this additional charge. The heat being continued the coal in the lower portion of the digester becomes a relatively solid mass of coke-like material from which the volatiles have been mainly eliminated leaving only sufiicient volatiles to make the fuel product readily ignitable.

As soon as the material in the lower osition of the digester is sufiiciently heated the lower end of the digester is opened by unlocking the bottom 4 and permitting it. to swing down and the plunger is again forced down to force the contents of the digester downward until the lower end of the expelled mass strikes the bottom 21 of the bin 20 and its further movement is prevented, the digester being thus left filled for about half its length, the partly treated material previously in the upper portion of the digester being forced down into the lower portion or highly heated zone of the digester ready to have its treatment there completed by the action of the heat by which the volatiles are more completely driven off and the tarry material rendered soft and in condition to hold the particles of solid matter together so that when com ressed the material in this lower zone will e rendered solid, compact and dense.

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nseaeee col of the diameter oft the digester which edectually plu s the end opening and prevents the out ow of the less solid partly treated material from the upper or cooler zone. I

The preferred temperature for the lower zone should be about 800 deees l at its most highly heated point an the temperature of the upper zone about 600 degrees in its coolest portion.

Alter the mass has been thus expelled from the digester it should be cut 0d and the bottom 4 closed.

The plunger being withdrawn more coal is run into the digester until it is filled and .the plunger is operated to compress the charge. The 0 eration of heating, until the coal is softened, compressing, further heating and expellin the lower portion of the charge is repeate the operation being thus substantially continuous.

The operation has been described as con ducted with a single digester but it is to be understood that two or more digesters are to be used.

The superheated steam is discharged through the perforations throughout the lower portion of the charge and this steam aiding in equalizing the heat throughout the charge finds its exit through openings 50 in the upper end of the digester and through pipe 40 to the dust collector carrying with it the volatiles in the form of vapors and gas and more or less solid matter which is eliminated by the dust collector.

I do not herein claim the carbonizing process carried out by the aparatus herein shown, described and claims as that forms the subject-matter of a separate application for patent for carbonizing process Serial No. 110948, filed May 2a, 1926.

Having thus described my invention what I claim is 1. ln apparatus for carbonizing coal, a vertically arranged digester tube adapted to contain coal having an inlet near its upper end and having a bottom closure adapted to be opened to permit the contents of the digester tube to be discharged downward, a piston fitting the interior of the digester tube and means for raisin the piston to a point above the inlet and forcing it downward against the contents of the digester tube, heating means exterior of the digester tube near its lower end for heating the digest-er tube and its contents, and a bin below the lower end of the digester tube in position to receive its contents the bin being provided with means in line with the digester tube at a distance from its lower end less than the vertical height of the digester tube adapted to stop the discharge of the contents of the digester tube so as to leabve a portion thereof within the digester tu e. i

2. in apparatus for carbonizin coal, a vertically arranged digester tube a opted to contain coal having an inlet near its upper end and having a bottom closure adapted to be spread to permit the contents of the digester tube to be discharged downward, a piston fitting the interior of the digester tube and means for raising the piston to a point above the inlet and forcing it downward against the contents of the digester tube, heating means exterior of the digester tube near its lower end for heating the digester tube and its contents, vertical pipes within the digester tube extending through the piston and provided with perforations near their lower ends, means for supplying superheated steam to said vertical 'pes' comprising pipes arranged about/the igester tube in osition to be heated by said burners, a bin below the lower end of the digester tube in position to receive its contents the bin being provided with means in line with the di ester tube at a distance from its lower on less than the vertical height of the digester tube adapted to stop the discharge of the contents of the digester tube so as to-leave a portion thereof within the digester tube, means for preheatin the coal, and means for conveying the con dischar ed from the preheater to the inlet of the digester tube.

In testimony whereof, I hereunto afiix my signature.

CHAS. YES.

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